The present invention relates to a braking device particularly for skates.
The problem of braking the wheels in order to adjust the speed of the skate is currently felt in conventional roller skates, whether constituted by a shoe associated with a support for two pairs of mutually parallel wheels or constituted by a shoe associated with a supporting frame for a plurality of aligned wheels.
In conventional skates, adapted blocks or pads, usually made of rubber, are placed at the toe or heel regions and when the user tilts the shoe forwards or backwards, the pad interacts with the ground and braking is thus achieved.
The drawback of these conventional brakes is that the user must rotate the whole skate jeopardizing his/her balance.
U.S. Pat. No. 1,402,010 discloses a roller skate having a strap that can be fastened on the user's leg above the malleolar region, a rod being connected thereto.
The rod surrounds the rear of the leg and is curved so as to laterally affect said leg. The rod ends are associated, in the malleolar region, with a lever assembly that is articulated to a structure that protrudes from the wheel supporting frame.
The lever assembly protrudes at the rear of the frame and is connected to a plate shaped approximately complementarily to the curvature of part of an underlying and facing wheel.
This solution has drawbacks: first of all, a relative motion occurs between the strap and the leg throughout sports practice, and this does not make its use comfortable due to the continuous rubbing of the strap on the leg.
Furthermore, the plate is activated every time the user bends his leg backwards beyond a given angle, without true and easy possibility of varying this condition.
Still, since the shape of the leg is different for each user, braking is achieved for different rotation angles for an equal rod length.
The rod also acts and presses in the malleolar region, and this can cause discomfort or produce accidental impacts during sports practice.
Finally, considerable wheel wear is observed, forcing continuous replacement of said wheels and accordingly increasing costs.
U.S. Pat. No. 4,275,895 discloses a brake acting on the rear wheels of a skate with mutually parallel pairs of wheels.
Said brake is constituted by a flap associated with the shoe in a rearward position; a blade is associated in a rearward position with said flap and is pivoted at the supporting frame of the shoe.
Said blade has, at its free end, a transverse element, two C-shaped elements being formed at the lateral ends thereon; said elements interact, following a backward rotation applied to the flap, with the rear wheels facing them, so as to interact with the rolling surface of said wheels.
However, even this solution has drawbacks: it is in fact structurally complicated and therefore difficult to industrialize; it also has adapted springs for repositioning the flap in the condition in which the two C-shaped elements do not interact with the wheels, and this further increases structural complexity.
Furthermore, the structural configuration of the brake causes the two C-shaped elements to interact with the wheel even upon a minimal backward rotation applied to the flap and therefore even for involuntary movements, thus producing unwanted braking actions and, accordingly, possible loss of balance or coordination.
Finally, the interaction of the C-shaped element at the rolling surface of the wheels leads to their rapid wear and therefore to non-optimum rolling, which necessarily leads to continuous replacement of said wheels.
U.S. Pat. No. 4,300,781 discloses a brake for skates having pairs of mutually parallel wheels.
The brake is constituted by a blade pivoted transversely at the rear end of the supporting frame for a shoe; pads are associated with the ends of said blade and face the rolling surface of the pair of rear wheels.
The brake is operated by using a cable adapted to rotate the blade in contrast with a spring that is associated with the support for the pair of front wheels, so as to move the pads into contact with the rolling surface of the pair of rear wheels.
Said cable is activated by means of rings or handles associated with a strap that can be placed on the user's legs by means of temporary connection means.
However, this solution has considerable drawbacks; first of all, brake activation can lead to possible loss of balance during sports practice, because the user's body does not assume a position that can control the sudden speed reduction; only the skater's hand is in fact involved in the activation of the brake.
Furthermore, as sports practice can occur while wearing trousers, when traction is applied to the rings the strap may slip along the trousers or drag them so that they slide along the leg, thus hindering the braking action.
Furthermore, there is a loose cable that, in addition to being a hindrance to the skater, can accidentally catch during racing, especially because coordination of the armleg movement causes the legs to move rhythmically laterally outwards.
U.S. Pat. No. 4,033,596 discloses a roller-ski that has, in addition to engagement means for the tip of a shoe, braking means substantially constituted by a bar that protrudes above a supporting frame for the shoe in the rear region thereof; said bar is pivoted transversely to said frame at one end and has, at the other end, a curved plate for supporting the user's calf.
A frame is associated transversely and to the rear of the bar; once the bar has been rotated backwards, said frame interacts with the rolling surfaces of two wheels that are in turn freely pivoted to the supporting frame for the shoe.
This brake cannot be efficiently used for roller skates, because skating entails continuous oscillations of the leg that can lead to unwanted activations of the braking action.
Moreover, the presence of the bar would be dangerous for the user, constituting a blunt body that is completely independent of the leg and might therefore be dangerous in case of a fall.
Furthermore, the described solution does not allow to achieve a gradual braking action.
U.S. Pat. No. 5,388,844 granted on Feb. 14, 1995 discloses a braking device comprising a rod member connected to the shoe quarter and sliding with respect to the shell. The rod member has a fork-like end that interacts with one or more of the wheels beyond a preset backward rotation angle of the quarter.
Although this solution is undoubtedly an improvement and is valid, it has some small drawbacks related to the fact that it is not possible to easily achieve good graduality in the braking action, as this is mainly entrusted to the skill and sensitivity of the user.
U.S. patent application Ser. No. 08/115.416 filed Sep. 1, 1993 discloses a braking device comprising a rod member that can slide with respect to the shell, is pivoted transversely to the shoe quarter at one end, and lies above, or is associated with, a braking element at the other end; said braking element is oscillatably articulated to said frame and selectively interacts with the ground.
Although this solution is undoubtedly valid, it has the drawback that it does not allow optimum alignment of the brake with the ground when the shell is shifted laterally with respect to the frame; this condition is provided by the user, both for roller skates and for ice skates, if he wishes to customize the configuration of the skate, for example to improve lateral thrusting, according to the sport practiced and to the shape of his foot.